The present invention relates to a joint consisting of two parts, a male part and a female part, which makes it possible to couple the ends of two pipes, at least one of which is flexible, the coupling being affected rapidly and automatically through a simple insertion of the male part into the female part, as well as to uncouple, likewise rapidly, the two parts through the manual operation of a ring arranged externally on the female part.
Joints of this kind are widely known and used in various fields, e.g., for connecting electrical household machines, such as washers, dishwashers and the like, to feeding water pipes. A particularly broad use is found in gardening, where flexible pipes are used for feeding water to various types of devices, e.g., sprinklers and the like.
A large portion of such joints comprises elements of spherical or other shape, that are arranged in various ways in one of such parts, usually in the female part, and engage an annular groove provided in the other part, usually in the male part, thus securing the coupling of the parts. Both for coupling and also the uncoupling it is normally necessary to operate a ring usually arranged on the female part. Some solutions also provide the possibility of automatic coupling obtained simply by inserting one part into the other, while uncoupling always requires the operation of a special ring.
One of such solutions is described in German Pat. No. P 1,775,302 in the name of Kupex A. G., intended especially for use in gardening. A second such solution is described in British Pat. No. 1,066,637 of Hoover Limited, concerning the attachment of a flexible pipe to a vacuum cleaner.
Such embodiments, while solving the problem of effecting the coupling rapidly and automatically simply by inserting the male part into the female part, providing a secure reciprocal fastening of the parts and effecting the uncoupling by acting ordinarily with one hand on a special release ring, are associated with various disadvantages. The joint of German Pat. No. P 1,775,302 is very complex in structure, both when provided with a rotatable release ring and also when provided with a longitudinally displaceable release ring. Actually, it provides a series of release elements freely inserted into suitable recesses, that also require positioning tangs or springs and certainly cause difficulties in assembly. Besides, the ring requires a spring, which is an element separate from the ring and which may be a torsion spring or a compression spring in accordance with the two embodiments. The complexity of structure and assembly results in a reduced reliability even under normal operating conditions. However, especially when used for irrigation, i.e., with pipes in contact with the soil or placed underground, such joint is subjected to the entry of soil and dirt, which readily plugs up the recesses within which it is necessary to shift and operate the locking and control elements, such recesses being very small in dimensions, so that any operation of such joint becomes difficult or even impossible.
British Pat. No. 1,066,637 substantially differs from the above-mentioned German Pat. No. P 1,775,302 only through a different structural shape, which is more suitable for the object intended, namely, the coupling of a flexible pipe to a vacuum cleaner element. However, the operational principle is practically the same. In fact, such joint is likewise provided with elastic cam elements that are feely inserted between the control ring and the male part, such elements having an inclined surface, so as to allow the insertion and automatic coupling of the male part in the female part, and a surface which effects a seal in an annular groove provided in the female part. Besides, there is provided also a sealing ring, arranged at the end of the male part and effecting a seal between the latter and the ring for controlling uncoupling, and another ringtype sealing element arranged on the female part and effecting seal between the latter and the said control ring. There are no substantial practical differences that could not be overcome by an average technician in order to derive from this joint the solution of the German Pat. No. P 1,775,302, which is mentioned above. Therefore, also the solution of the British patent is associated with all the disadvantages already mentioned in regard to the German patent. Besides, as mentioned in the patent itself, there is required a considerable precision in manufacturing the various components with very narrow tolerances. In fact, in order to effect the coupling and also the uncoupling in some cases where such structural tolerances are not observed, there is required a double action with two hands, one for handling the control ring and one for acting at the same time in a suitable manner on the male part.